I see a lot of "should"s. When push comes to shove, though, a notification is not going to change the behavior of the network.
There's a lot of complaints I have about how some networks (especially mobile ones) deviate from RFCs and break specifications. A 30 second timeout is not nearly at the top.
If people are violating the RFCs then applications that detect it should probably start notifying users exactly why their battery life is suffering.